Added NettyDiscoveryBaseHandler and packet size validation

src/Nethermind/Nethermind.Network.Discovery.Test/NettyDiscoveryV5HandlerTests.cs

@@ -12,6 +12,7 @@
 using DotNetty.Transport.Channels.Sockets;
 using FluentAssertions;
 using Microsoft.Extensions.Logging;
+using Nethermind.Logging;
 using Nethermind.Serialization.Rlp;
 using NSubstitute;
 using NUnit.Framework;
@@ -29,7 +30,7 @@ public class NettyDiscoveryV5HandlerTests
         public void Initialize()
         {
             _channel = new();
-            _handler = new(new LoggerFactory());
+            _handler = new(new TestLogManager());
             _handler.InitializeChannel(_channel);
         }
 

src/Nethermind/Nethermind.Network.Discovery/Discv5/DiscoveryV5App.cs

@@ -91,7 +91,11 @@ .. _discoveryDb.GetAllValues().Select(enr => enrFactory.CreateFromBytes(enr, ide
             .WithTableOptions(new TableOptions(bootstrapEnrs.Select(enr => enr.ToString()).ToArray()))
             .WithEnrBuilder(enrBuilder)
             .WithLoggerFactory(new NethermindLoggerFactory(logManager, true))
-            .WithServices(NettyDiscoveryV5Handler.Register);
+            .WithServices(s =>
+            {
+                s.AddSingleton(logManager);
+                NettyDiscoveryV5Handler.Register(s);
+            });
 
         _discv5Protocol = discv5Builder.Build();
         _discv5Protocol.NodeAdded += (e) => NodeAddedByDiscovery(e.Record);

src/Nethermind/Nethermind.Network.Discovery/Discv5/NettyDiscoveryV5Handler.cs

@@ -9,24 +9,24 @@
 using DotNetty.Transport.Channels.Sockets;
 using Lantern.Discv5.WireProtocol.Connection;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
+using Nethermind.Logging;
 using Nethermind.Serialization.Rlp;
 
 namespace Nethermind.Network.Discovery;
 
 /// <summary>
 /// Adapter, integrating DotNetty externally-managed <see cref="IChannel"/> with Lantern.Discv5
 /// </summary>
-public class NettyDiscoveryV5Handler : SimpleChannelInboundHandler<DatagramPacket>, IUdpConnection
+public class NettyDiscoveryV5Handler : NettyDiscoveryBaseHandler, IUdpConnection
 {
-    private readonly ILogger<NettyDiscoveryV5Handler> _logger;
+    private readonly ILogger _logger;
     private readonly Channel<UdpReceiveResult> _inboundQueue;
 
     private IChannel? _nettyChannel;
 
-    public NettyDiscoveryV5Handler(ILoggerFactory loggerFactory)
+    public NettyDiscoveryV5Handler(ILogManager loggerManager) : base(loggerManager)
     {
-        _logger = loggerFactory.CreateLogger<NettyDiscoveryV5Handler>();
+        _logger = loggerManager.GetClassLogger<NettyDiscoveryV5Handler>();
         _inboundQueue = Channel.CreateUnbounded<UdpReceiveResult>();
     }
 
@@ -50,7 +50,7 @@ public async Task SendAsync(byte[] data, IPEndPoint destination)
         }
         catch (SocketException exception)
         {
-            _logger.LogError(exception, "Error sending data");
+            if (_logger.IsError) _logger.Error($"Error sending data", exception);
             throw;
         }
     }

src/Nethermind/Nethermind.Network.Discovery/NettyDiscoveryBaseHandler.cs

@@ -0,0 +1,41 @@
+// SPDX-FileCopyrightText: 2024 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using DotNetty.Transport.Channels;
+using DotNetty.Transport.Channels.Sockets;
+using Nethermind.Logging;
+
+namespace Nethermind.Network.Discovery;
+
+public abstract class NettyDiscoveryBaseHandler : SimpleChannelInboundHandler<DatagramPacket>
+{
+    private readonly ILogger _logger;
+
+    // https://github.com/ethereum/devp2p/blob/master/discv4.md#wire-protocol
+    // https://github.com/ethereum/devp2p/blob/master/discv5/discv5-wire.md#udp-communication
+    protected const int MaxPacketSize = 1280;
+
+    protected NettyDiscoveryBaseHandler(ILogManager? logManager)
+    {
+        _logger = logManager?.GetClassLogger<NettyDiscoveryBaseHandler>() ?? throw new ArgumentNullException(nameof(logManager));
+    }
+
+    public override void ChannelRead(IChannelHandlerContext ctx, object msg)
+    {
+        if (msg is DatagramPacket packet && AcceptInboundMessage(packet) && !ValidatePacket(packet))
+            return;
+
+        base.ChannelRead(ctx, msg);
+    }
+
+    protected bool ValidatePacket(DatagramPacket packet)
+    {
+        if (packet.Content.ReadableBytes is 0 or > MaxPacketSize)
+        {
+            if (_logger.IsWarn) _logger.Warn($"Skipping discovery packet of invalid size: {packet.Content.ReadableBytes}");
+            return false;
+        }
+
+        return true;
+    }
+}

src/Nethermind/Nethermind.Network.Discovery/NettyDiscoveryHandler.cs

@@ -11,10 +11,11 @@
 using Nethermind.Core.Extensions;
 using Nethermind.Logging;
 using Nethermind.Network.Discovery.Messages;
+using ILogger = Nethermind.Logging.ILogger;
 
 namespace Nethermind.Network.Discovery;
 
-public class NettyDiscoveryHandler : SimpleChannelInboundHandler<DatagramPacket>, IMsgSender
+public class NettyDiscoveryHandler : NettyDiscoveryBaseHandler, IMsgSender
 {
     private readonly ILogger _logger;
     private readonly IDiscoveryManager _discoveryManager;
@@ -27,7 +28,7 @@ public NettyDiscoveryHandler(
         IChannel? channel,
         IMessageSerializationService? msgSerializationService,
         ITimestamper? timestamper,
-        ILogManager? logManager)
+        ILogManager? logManager) : base(logManager)
     {
         _logger = logManager?.GetClassLogger<NettyDiscoveryHandler>() ?? throw new ArgumentNullException(nameof(logManager));
         _discoveryManager = discoveryManager ?? throw new ArgumentNullException(nameof(discoveryManager));
@@ -80,7 +81,7 @@ public async Task SendMsg(DiscoveryMsg discoveryMsg)
         }
 
         int size = msgBuffer.ReadableBytes;
-        if (size > 1280)
+        if (size > MaxPacketSize)
         {
             if (_logger.IsWarn) _logger.Warn($"Attempting to send message larger than 1280 bytes. This is out of spec and may not work for all client. Msg: ${discoveryMsg}");
         }